OPNET Interest Group

Introduction

OPNET is a powerful and complete simulation tool which is being adopted worldwide by numerous Universities, R&D labs, manufacturers and operators. Contains simulation modules for the main telecommunications systems (UMTS, WLAN 802.11 and mesh networks, WIMAX 802.16, Zigbee 802.15.4), being possible to modify them or create new ones. It uses a comprehensive language based in C++, containing a good graphical interface. It enables the computation of a large set of performance results. All developed modules within universities are available online.

Educational Activities

A comprehensive tutorial on the OPNET Modeller simulation tool was given by Gonçalo Carpinteiro in an internal seminar to GROW members, presenting the main advantages of this simulation tool by opposition to others, and giving a short overview of its potentialities. Many undergraduate and graduate researchers are starting to adopt this simulation tool.

Research Activities

The OPNET Modeler simulation tool is used to simulate an LTE network using the MBMs service. The advantages of MBMS and influence of various factors such as inter-cell distance, modulation, mobility is evaluated. For evaluation is used the MOS model based on packet loss statistics.

OPNET is being used as a tool to estimate EMF Exposure in a given set of scenarios, using heterogeneous networks, including LTE, UMTS, TDMA and WiFi networks. Special “sensor” nodes were created to listen all radio packets from all the systems, with separation for the base stations and the mobile nodes. For such, some modifications were also done in the radio pipeline stages of all the nodes. This will enable us to study the impact of different system parameters on exposure using OPNET as the simulation tool.

The OPNET Modeler simulation tool was used to simulate a wireless mesh network of access points connected via a wireless backhaul network using IEEE 802.11 standard (for several extensions, including the IEEE 802.11s) and 802.16 WIMAX. The establishment of connections and management of resources between users and Access Points and also between Access Points that wirelessly route the information as a backhaul is going to be simulated. The work will be focused on algorithms and solutions developed for the PHY and MAC layers.

Common radio resource management in a heterogeneous network infrastructure, by Luísa Caeiro (PhD thesis, 2008-2010)

In a first stage, Wimax OPNET module will be used to study the QoS impact in the performance of several type of services in a heterogeneous network infra-structure, where Wimax is used for the last mile access network. In a second phase, where new Common Radio Resource Management algorithms will be proposed, the Modeler simulation tool of OPNET is planned to be used for evaluating and assessing the proposed algorithms.

This thesis attempts to ease the work of network operators by introducing and analyzing advanced network monitoring and automated planning and optimization methods. The focus of this work will set on 3G/4G mobile radio access network parameter optimization using rule-based methods and intelligent algorithms with the objective of improving network performance as measured in capacity and quality. Related with intelligent algorithms, Self Organizes Maps and Genetics algorithms will be studied and applied to the problem resolution. Several parameters will be study and applied to optimization algorithms. The admission control function determines the amount of traffic allowed in each base station cell. Other key contribution areas include automated optimization of 3G/4G radio network parameters such as the pilot power and handover parameters Also simultaneous optimization of different parameters will be validated. The optimization methods used will rule-based and the main optimization objective was improving the network performance with regards to network quality or capacity. In conflicting situations a trade-off between capacity and quality was preformed. Statistical testing and policies describing allowed performance indicator levels and trade-off preferences will used in the optimization. The automated optimization methods will be validated using a 3G/4G system level simulator. Simulation scenario wills considerer a traffic profile modeling in multi-service environments.

Mobile ad hoc networks by Jose Mocito (PhD thesis, 2008-)

The OPNET simulator will be used to evaluate a set of enabling technologies that we are developing to provide better support for heterogeneous mobile ad hoc networks, including: 1) an adaptive flooding algorithm capable of self-configuring its parameters according to the perceived network conditions; 2) a unicast/multicast protocol that addresses special requirements of networks with heterogeneous mobility; 3) a novel communication infrastructure, that integrates a specialized tuple-space service with the result listed above, to support emergency management activities; and 4) novel protocols for multi-path routing.

The work is focused on the new IEEE 802.11e standard, and its new solutions. The enhancements proposed within the IEEE 802.11e standard aim to provide QoS guarantees to applications but some issues to enable a comprehensive QoS support to applications remain. The work will be focused on developing new alghoritms for a better QoS support to applications while using IEEE 802.11e. The Modeler simulation tool of OPNET is currently being used to simulate different scenarios and evaluate the proposed alghoritms in order to provide QoS guarantees to applications.

OPNET Modeler is currently being used to simulate the backbone of an 802.11 based mesh network. Namely, a complete analysis of a one hop connection performance will be performed, focusing on the achieved improvements of using different 802.11 standards for access and backbone networks. Several parameters will be evaluated (throughput and QoS requirements), considering the usage of a end to end user applications mix.

Objective: to analyse the capacity and performance of a Wireless Mesh Network based on IEEE 802.11 WLANs for a Residential Scenario. The aim of this thesis is to study the performance of a WMN in a Residential Scenario, composed mostly by two floor residential houses, surrounded by streets and trees. This scenario extends itself over a large area of some square kilometres covered by a large backhaul network. Each MAP covers a specific area, where small communities of residential users use a set of services. The number of users is relatively low, and the usage of services is not intense, high traffic load levels not being expected. This WMN scenario will be characterised with several possible service mixes. Its performance will be evaluated, considering several characteristics of the scenario (number of users per MAP, number of MAPs, number of gateways, number of hops), using OPNET Modeller Wireless Suite simulation tool.

The objective of this work is to analyse the capacity and performance of a Wireless Mesh Network based on IEEE 802.11 WLANs for a Campus Scenario. A Campus Scenario is composed by several buildings surrounded by open areas and corresponds to a small area covered by a small backhaul network. This campus concentrates a high density of users, resulting in high traffic loads in each Mesh Access Point (MAP), as well as in the whole backhaul network. Its performance will be evaluated, considering several charachteristics of the scenario, using OPNET Modeller Wireless Suite simulation tool.

Traffic Analysis of GEANT academic network addressing prediction of network congestion patterns. This will enable a forecast of these situations, giving to network operators more knowledge on the network in order to act in advance. OPNET will be used to build the GEANT network, load the dataset with the input and output information from the GEANT network routers and then run the simulation in order to collect the traffic passing by the different links, enabling the modeling of traffic evolution.

A comparative QoS performance analysis, using OPNET Modeller, is presented of two architectures for the provision of a set of services (VoIP, HTTP, E-mail and FTP) to isolated villages without any fixed telecommunications infrastructure, equipped only with a fixed or satellite gateway. One architecture covers users with a Wireless Mesh Network (WMN) of WLAN APs, and another with a single WIMAX BS. Is evaluated the impact in QoS of the increase of number of users.